LED Array Orientation for Uniform Projection Lighting
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Solution Overview
Problem
Conventional LED-based projection lighting fixtures face issues with non-uniform irradiance and spectral distribution due to the imaging of LED package shapes and color disparities, leading to undesirable irradiation patterns and spectral non-uniformity in target illumination fields.
Innovation Solution
The arrangement of LED light sources on a common mounting board with strategically selected orientations and rotations to ensure overlapping light projections, utilizing collimating optics to achieve uniform illumination, particularly by aligning light sources relative to a common reference axis and rotating them to minimize the impact of package geometry and color variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional LED packages with fixed orientations are used, then the structure is simple and easy to manufacture, but the irradiance distribution is non-uniform due to package shape imaging
Solution Approach 1:
The patent applies asymmetry by deliberately orienting LED packages at different rotations and angles relative to a common reference axis. This asymmetric arrangement prevents the regular geometric patterns that cause imaging effects, thereby achieving uniform irradiance distribution across the target field while maintaining simple manufacturing processes.
2Illumination intensity
If multiple LED packages with different colors are used, then the color spectrum is enhanced, but spectral non-uniformity occurs due to color disparities
Solution Approach 1:
The patent applies local quality by assigning different orientations and rotations to LED packages based on their specific color characteristics. Each color group (e.g., red, green, blue, white) is oriented at specific angles relative to the common reference axis, ensuring that spectral components are uniformly distributed across the target field while maintaining enhanced color spectrum.
3Device complexity
If LED packages are arranged without strategic orientation, then the device complexity is low, but the light projection overlap is insufficient leading to non-uniform illumination
Solution Approach 1:
The patent applies segmentation by dividing the LED array into multiple groups, each oriented at different rotations and angles relative to a common reference axis. This segmentation ensures that light projections from different packages overlap strategically across the target field, achieving uniform illumination while maintaining relatively low device complexity through systematic arrangement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces irradiance and spectral non-uniformity, achieving substantially uniform illumination and improved color mixing in the target field, enhancing the directional focus and color consistency of the projected light.
Implementation Method 1
A TIR collimator includes a reflective inner surface that is positioned to capture much of the light emitted by a light source subtended by the collimator. The reflective surface of conventional TIR collimators is typically conical... Some of the light travels from source 112 through a primary optic 114, into a first cavity 116, through a centrally-located lens 118... The remainder of the light exits via a transparent surface 122 or a flange 124... The light that does not pass through the central lens is incident on an inner sidewall 126 and is refracted as it passes from the air in the first cavity into the plastic material of the collimator. Thereafter, it is reflected at an inner reflective surface 129.
Implementation Method 2
The light that does not pass through the central lens is incident on an inner sidewall 126 and is refracted as it passes from the air in the first cavity into the plastic material of the collimator.
Data Source
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AI summary
A projection lighting (300) fixture includes multiple LED packages (301) (e.g., chip-on-board or surface mount LED assemblies including one or more LED junctions) disposed on a common mounting board or substrate (302). Each LED package is associated with a corresponding collimator (315). The common mounting board on which the multiple LED package/collimator pairs are disposed includes a reference axis (510) in the plane of the board (e.g., a vertical or horizontal axis of the board). One or more of the LED packages are disposed on the common mounting board such that they are rotated clockwise or counter-clockwise with respect to the reference axis (510), so that at least two of the LED packages have different rotations. The light projected from the respective collimators associated with the multiple LED packages at least partially overlaps in a target illumination field (310), and the different rotations of at least two of the LED packages facilitates substantially uniform illumination in the target illumination field.